A network may comprise nodes, which may diskless nodes, and one or more servers. The communications within the network may be made according to a network protocol (first protocol). Another protocol (second protocol) may be used additionally, e.g. for the communications between a node and a server.
An example of second protocol is the “Dynamic Host Configuration Protocol”, or DHCP protocol. It makes it possible for a network node to automatically obtain an IP address from a DHCP server. The IP address may be valid for a predetermined period of time, in a so-called “IP address lease” mode. Upon expiration of such an “IP address lease”, the DHCP protocol further permits that the node either keeps the same IP address, or gets a new one.
The DHCP protocol is of interest in networks operating with diskless nodes, i.e. being deprived from a bootable local hard drive and from other bootable devices. In such networks, the diskless nodes will have to boot otherwise, e.g. via DHCP.
Problems may occur with nodes attempting to boot via DHCP. Then, the diagnosis of such a problem is much harder to do than with a conventional computer, since little or no information on what happened is accessible. The diagnosis becomes even more complicated in high availability clusters with many diskless nodes, while several DHCP servers are available in the same subnet. As known, a subnet is a set of computers connected to one or more servers which share a common IP address portion, e.g. a common IP address prefix.
The prior art comprises utilities capable of starting a DHCP handshaking, by generating a discover message (“DHCPDISCOVER”). However, those utilities can only be used with a local existing network interface of a computer or node. Thus, they do not offer any flexibility of network interface emulation. Moreover, after a successful DHCP handshaking, those utilities will proceed to finish with the DHCP protocol sequence. Thus, they will assign the new dynamic configuration to the local computer or node, and perform modifications to the DHCP tables in the server accordingly. This also influences the condition of the network, which is undesirable at the time of debugging.
In the event a user is trying to diagnose the network for an issue with the DHCP servers, those utilities are unadapted. Here and in the following description, the term “user” is used to refer to a person trying to use the boot-faltering computer, a network maintenance personnel or any person qualified to try and solve the problem being encountered.
The invention aims at improving the situation.